How is a dam dewatering project executed using tunnel boring machines?

Q: How is a dam dewatering project executed using tunnel boring machines?

The execution of a dam drainage with tunnel boring machines requires a geotechnical study of the terrain, design of the layout, construction of attack and exit shafts, and excavation with closed shield or hydroshield tunnel boring machines. Eurohinca installs the ducts by means of microtunneling with maximum precision, complying with hydraulic regulations and ensuring watertightness, flow control and structural safety.

🏞️ What is a weir drain and why is microtunneling used?

Bottom drains in dams make it possible to control the reservoir level, perform maintenance or emergency drains, and ensure the stability of the infrastructure. Trenchless technology such as microtunneling makes it possible to excavate with pinpoint accuracy under high hydrostatic pressure conditions.

🔧 Key phases of execution with tunnel boring machines.

Geotechnical study of the soil
Hydrogeological conditions, water pressure and ground cohesion are evaluated.
Technical design and engineering of the layout
The tunnel is designed according to the required flow rate, duct materials and depth.
Preparation of attack and exit wells
Safe chambers are built to launch and retrieve the tunnel boring machine with minimum disturbance.
Excavation with closed shield or hydro shield TBMs
Drilling is performed with controlled pressure, avoiding infiltrations and collapses.
Drain line installation
Steel or GRC pipes are laid with sealed joints to withstand extreme pressures.
Hydraulic testing and structural sealing
Flow, pressure and tightness tests are performed prior to commissioning.

🛠️ Specialized technology and applicable regulations

Eurohinca employs pressurized tunnel boring machines, laser guidance systems, EPB shields o hydroshields and certified safety protocols (ISO 9001, 45001).

Find out more about our hydraulic works with microtunneling.